YOKOSUKA, Japan — A new safety feature being developed by Nissan Motor Co. causes a car's gas pedal to lift by itself to alert the driver of a possible collision.

That new technology, shown to reporters this week, combines radar sensors and a computer system to judge a car's speed and the distance to the vehicle in front.

When the car senses a possible head-on crash, the gas pedal automatically rises against the driver's foot as a signal to step on the brake.

If sensors detect a possible collision ahead, the brake automatically kicks in when the driver lifts his or her foot off the gas.

A buzz also goes off in what Nissan engineers tentatively dubbed the "magic bumper."

Skeptics may see the technology as obtrusive, perhaps even risky, given that some drivers may prefer to rely on their own reflexes.

But Nissan says the magic bumper is helpful because research has shown that more than half of traffic accidents are caused by inattention, drowsiness and carelessness, rather than error in judgment and or illegalities such as speeding and drunken driving.

It's a safety feature that comes in particularly handy on congested roads, the Japanese auto maker said.

Senior manager Yousuke Akatsu hopes to offer the feature in about two or three years in Japan, and also aims to offer it in the United States and Europe, although no plans have been set.

The technology is part of the Tokyo-based company's larger effort to create the accident-proof car. So far, Nissan offers cruise control, warnings for cars veering off lanes and a system that helps drivers brake harder in emergencies.

Also shown in a demonstration at a facility near Tokyo was a car-navigation monitor that uses digital cameras lodged in the front and back of the car, as well as in the sideview mirrors, to show a computer-graphic bird's eye view of the car.

The AVM, or "around view monitor," shows what's surrounding the car from all around, putting together photo images from the cameras to help drivers steer into tight parking spots — very useful in a crowded country like Japan.

Commercial plans for the feature are still undecided, according to Nissan.

Nissan officials demonstrated a paint job offered in Japan that fixes itself of slight scratches caused by car-washing, off-road driving or fingernails. To speed up the repair of the elastic resin, which works like a rubbery surface, hot water was poured on a surface after it was scraped with a bristled metal brush.

All these features are part of the ongoing competition among major automakers around the world to attract buyers, and the fancy ones still tend to come in expensive models.

From Toyota Motor Corp. is Intelligent Parking Assist system, in which the car parks by itself — even if the driver has no hands on the steering wheel — calculating from its built-in computer, steering sensor and a tiny camera in the rear the proper route into a parking spot.

U.S. automaker General Motors Corp. has said it plans to make electronic stability control standard on all of its light-duty trucks by 2010. Ford Motor Co. has shown an experimental inflatable seat belt that deploys inside the shoulder belt in a crash, adding protection to the chest.